1. Field of the Invention
The present invention relates to a cassette (storage) case which is suitable for inserting and accommodating a tape cassette such as an audio compact cassette or the like, and in particular, to a slide type cassette accommodation case which can insert and take out a cassette in a manner of sliding the cassette in a transverse direction from an insertion opening formed on one side of the cassette accommodation case.
2. Description of the Related Art
In recent years, in a cassette accommodation case for inserting and accommodating an audio compact cassette, a slide type cassette accommodation case has been practically used which slidably inserts and takes out a cassette in a manner of sliding the cassette in a transverse direction from an insertion opening formed on one side of the cassette accommodation case.
FIG. 1 to FIG. 4 each show a structure of a conventional slide type cassette accommodation case.
The cassette accommodation case is constructed in a manner of combining a lower half 1 and an upper half 2. The lower half 1 is a plastic molding product which is molded of e.g., a HIPS (high impact polystyrene) material; on the other hand, the upper half 2 is a plastic molding product which is molded of e.g., a GPPS (general purpose polystyrene) material.
The lower half 1 and the upper half 2 are individually formed with half-cut like cassette insertion openings 3a and 3b at their one side, and a cassette (audio compact cassette) 4 shown in FIG. 9 is slidably inserted in and taken out of the insertion opening in a transverse direction.
The cassette 4 rotatably houses therein a pair of reel hubs 5 for winding up a magnetic tape, and an inner periphery of the reel hub 5 corresponds to each of a pair of hub driving shaft insertion holes 6 formed on a cassette housing body.
Also, one side of the cassette 4 is formed with a trapezoidal bulged portion 7 which constitutes a mouth portion where the magnetic tape is exposed, at both upper and lower sides of the cassette housing body.
The cassette 4 is inserted into the cassette accommodation case so that there is almost no gap. To this end, in an interior of the cassette accommodation case, on inner surfaces of the lower half 1 and the upper half 2 are formed with recess grooves 8a and 8b for receiving the bulged portion 7 of the cassette 4 in a transverse direction, that is, a cassette inserting direction, respectively.
The inner surface of the lower half 1 is fixed and attached with a rotation stopper member 9 for inhibiting an unnecessary rotation of the reel hub 5 of the cassette 4.
The rotation stopper member 9 is molded of a PP (polypropylene) resin, and is composed of a base plate 10 having a plurality of caulking holes 10a, and a pair of rotation stopper pieces 11 which stand up integrally from the base plate 10 and are elastically deformable. A distance between these rotation stopper pieces 11 corresponds to a distance between the hub driving shaft insertion holes 6 of the cassette 4.
Moreover, the rotation stopper piece 11 is formed with a notch 12 which reaches an upper surface of the base plate 10, at the center thereof, and thereby, the rotation stopper piece 11 is composed of two pieces 11a and 11b. The base plate 10 is formed with a U-shaped notch groove 13 around the rotation stopper piece 11.
The inner surface of the lower half 1, on which the rotation stopper member 9 is fixed, is formed a thin wall portion 1b for weight reduction in a state of leaving the recess groove 8a, the insertion opening 3a and a U-shaped thick wall portion 1a along a side wall 1d. The thin wall portion 1b is formed with a rib 16 having a shape surrounding a periphery of the base plate 10 of the rotation stopper member 9, and then, the base plate 10 is positioned by the rib 16.
The rib 16 is formed lower than the thick wall portion 1a, and a caulking pin 17 corresponding to the fastening hole 10a of the base plate 10 is projected from the thin wall portion 1b surrounded by the rib 16. Then, in a state that the fastening pin 17 is engaged with the fastening hole 10a of the base plate 10, the tip end portion of the fastening pin 17 is subjected to caulking by ultrasonic welding or the like, and thus, the rotation stopper member 9 is fixed on the thin wall portion 1b surrounded by the rib 16.
Further, the thin wall portion 1b surrounded by the rib 16 is formed with a receiving recess portion 14 corresponding to the notch groove 13 of the base plate 10, and a depth of the recess portion 14 is 0.4 mm, for example.
An inner surface of the lower half 1 is provided with a slip-off preventive member 18 for preventing the cassette 4 from slipping off from the cassette accommodation case in a state that the cassette 4 is housed therein.
The slip-off preventive member 18 is projectingly formed integrally with the lower half 1, and has an engaging protrusion 19 at its tip end portion. When the cassette 4 is housed in the cassette accommodation case, the engaging protrusion 19 of this slip-off preventive member 18 is engaged with a hole 4c formed in an erroneous erase preventive detection pawl 4b provided at a rear face portion 4a of the cassette 4, as shown in FIG. 3, and thereby, the cassette 4 is prevented from slipping off from the cassette accommodation case.
On the other hand, like the lower half 1, an inner surface of the upper half 2 is formed with a thin wall portion 2b for weight reduction in a state of leaving the recess groove 8b, the insertion opening 3b and a U-shaped thick wall portion 2a along a side wall 2d. The thin wall portion 2b is formed with a long window-like opening portion 20 in a depth direction at the substantially central portion of the upper half 2. In the case of taking out the cassette 4 housed in the cassette accommodation case, a user pushes out the cassette 4 by his finger through the opening portion 20.
Further, the thin wall portion 2b is formed with a rib 21 along a peripheral edge of the opening portion 20, and thereby, it is possible to improve a strength of the upper half 2 and hence to prevent its flexion. Also, the rib 21 is formed lower than the thick wall portion 2a.
Moreover, in order to readily assemble the lower half 1 and the upper half 2, the lower half 1 and the upper half 2 are both provided with positioning means.
The positioning means is as follows. As shown in FIGS. 1 & 2, on the lower half 1 side, positioning protrusions 15a and 15b are projected at both right and left sides on an inner side of a depth wall 1c; on the other hand, on the upper half 2 side, a positioning protrusion 15c is projected at the substantially central portion on an inner side of a depth wall 2c. In this case, the positioning protrusions 15a and 15b are formed higher than the depth wall 1c, side walls 1d and 1e of the lower half 1. Likewise, the positioning protrusions 15c is formed higher than the depth wall 2c, side walls 2d and 2e of the upper half 2. These positioning protrusions are formed with an inclined plane for positioning at their tip ends.
In the case of assembling the cassette accommodation case, the lower half 1 and the upper half 2 are combined with the use of the aforesaid positioning protrusions 15a, 15b and 15c, and then, their joint surface is fixed by ultrasonic welding or the like so that these upper and lower halves 1 and 2 are integrally combined.
When the cassette 4 is inserted into the cassette accommodation case constructed as described above, the bulged portion 7 of the cassette 4 is guided by the recess grooves 8a and 8b formed in the lower half 1 and the upper half 2, while upper and lower faces other than the bulged portion 7 of the cassette 4 are guided by the thick wall portions 1a and 2a of the lower half 1 and the upper half 2.
With the cassette inserting operation, the rotation stopper protrusion 11 of the rotation stopper member 9 initially falls in the receiving recess portion 14 of the lower half 1 by the notch groove 13 formed in the base plate 10, and thereafter, is elastically deformed in a manner of being pushed down by the end portion of the cassette 4. In this case, by the provision of the receiving recess portion 14, a load to the rotation stopper protrusion 11 by the cassette 4 is dispersed to two points, that is, a proximal portion and a slightly upward portion of the rotation stopper protrusion 11. Thus the load by the cassette 4 is reduced, and a durability of the rotation stopper protrusion 11 is increased while the rotation stopper protrusion 11 is readily and securely elastically returned to the original state.
Thereafter, when the cassette 4 is inserted into the deepest portion of the cassette accommodation case, the rotation stopper protrusion 11 corresponds to the hub driving shaft insertion hole 6 of the cassette 4, and thereby, the rotation stopper protrusion 11 is elastically returned and then, stands up so as to be engaged with the engaging protrusion 5a formed on the inner periphery of the reel hub 5, and thus, an unnecessary rotation of the reel hub 5 can be inhibited.
In a state that the cassette 4 is housed in the cassette accommodation case, the bulged portion 7 of the cassette 4 is held in the recess grooves 8a and 8b formed in the lower half 1 and the upper half 2 while upper and lower faces other than the bulged portion 7 of the cassette 4 being held in the thick wall portions 1a and 2a of the lower half 1 and the upper half 2.
Further, in a state that the cassette 4 is housed in the cassette accommodation case, as shown in FIG. 3, the engaging protrusion 19 of the slip-off preventive member 18 is engaged with the hole 4c formed in the erroneous erase preventive detection pawl 4b provided at the rear face portion 4a of the cassette 4, and thereby, the cassette 4 can be stably stored in the cassette accommodation case without slipping off the cassette accommodation case.
In the case of taking out the cassette 4 from the cassette accommodation case, the user pushes out the cassette 4 by his finger through the opening portion 20 of the upper half 2, and then, the cassette 4 is pushed out to some degree, and thereafter, the user grasps the cassette 4 by his hand so as to pull it out of the cassette accommodation case.
In a cassette take-out operation, the rotation stopper protrusion 11 of the rotation stopper member 9 is elastically deformed so as to be pressed down in a side opposite to the side when the cassette is inserted, and then, comes off the hub driving shaft insertion hole 6. Then, after the cassette is taken out, the rotation stopper protrusion 11 is again elastically returned to the original state of standing up.
As described above, in the conventional cassette accommodation case, when inserting and taking out the cassette, a great frictional force is generated between the inner surface of the cassette accommodation case and the cassette. For this reason, it is difficult to smoothly insert and take out the cassette; therefore, there is arisen a problem that the user has difficulty handling the conventional cassette accommodation case.